HobbyKing Q450 Quadcopter

by Red20RC | September 18, 2014 | (5) Posted in Projects

With the (hopefully) incoming new rules on RPAS classification here in Australia, I was looking for a sub-2KG frame that could be used for aerial filming. The HobbyKing Q450 Quadcopter seemed to be the ideal solution…

49725There’s no denying it, the HobbyKing Q450 Quadcopter is a direct clone of the DJI F450 “Flamewheel”. The only noticeable difference I can see is that whilst the DJI frame will set you back around $62, the HobbyKing clone comes in at a budget friendly $10. I’m sure someone out there can tell me the difference but at the moment I’m having a hard time working out how DJI (or rather its distributors) can justify charging the extra $50.

Anyway, here at Red20RC we are always looking for the best value route to a successful outcome so a Q450 frame along with some NTM2826 1100KV motors and Multistar ESCs were soon on their way. I already had an HKPilot APM 2.5.2 sitting on the bench looking for a home so the scene was set.

Filming setup…

51635Of course, this wasn’t going to be just a quadcopter for flying around the field. I wanted a stable filming platform. This was of course the driver for using the APM clone, the ability to altitude hold, loiter and return to launch a pre-requisite for steady filming. But what about mounting my trusty GoPro Hero 3 to get that perfect shot? Once again I had a look through the HobbyKing catalogue and read good things about theTarot 2D gimbal for GoPro type cameras.

At this point I usually go into a detailed build log but this project has been going for a long time with many twists and turns. I’m only going to give you the highlights and some nice pictures. Read on…

Build One

The first build of the HobbyKing Q450 Quadcopter progressed much as you would expect for a frame of this type. Everything screws together nicely although some preparation work was required soldering the power leads and ESCs to the excellent power distribution board that makes up the lower plate. Everything fits together nicely with the motors bolting directly to the arms.

The flight controller needed some isolation from the main frame so I used an old plate from the SK450, mounted on some cut-down foam earplugs – sounds wierd but it works well.

It was whilst trying to mount the gimbal however that I hit my first snag…

HobbyKing sells a great range of affordable “crab” landing gear that are just perfect for lifting your frame up out of the dirt so you can hang a gimbal. They even have rails set at the standard 60mm for clipping on a whole host of different gimbals. Unfortunately I soon discovered that the rail mount arms on the Tarot 2D are set at 50mm so were utterly useless on this frame. In the end I had to bodge a direct mounting to the bottom plate. Not ideal but it worked.

With the APM up top and the gimbal down below the only space left I had for batteries was between the plates, fortunately this space is quite large so anything up to a 5000mah 3 cell fit easily, although was difficult to secure without wedging it in with foam.

First flights…

The first few flights were conducted out behind the house and demonstrated a couple of things:

  1. It flew
  2. It didn’t fly very nicely!

I had spent a lot of time tuning the APM using the real-time tuning methods described on DIY Drones. By allocating different parameters to the channel 6 knob on the Taranis I was able to tune out the wobbles by holding the frame in my hand and adjusting the settings with the motors running. The result was a nicely locked in frame but it still seemed hard to keep still. Switching to altitude and loiter modes highlighted the problem as the frame instantly tried to drop out of the sky – something wasn’t right with the APM!

I did a few tests and discovered upon running the “compassmot” test that there was a LOT of interference from the ESCs. The only solution was to get the APM higher up…

More problems

It was during this initial testing phase that I hit my next problem. After re-attatching the gimbal I went up for another test flight. All was going well until, with a judder, the gimbal simply stopped working. Tests later revealed that whilst the board would initialise fine the motors simply locked into place and wouldn’t stabilise a thing. I got grumpy as I needed a gimbal for this frame and quickly had a replacement on the way in the form of a much cheaper Quanum 2D gimbal.

At this point I need to give a nod of thanks to the HobbyKing returns service. A lot of people knock HK, especially for their customer service, but I have never had a problem and my Tarot gimbal was quickly returned and replaced without a fuss.

Build Two

For the second build I stripped everything down once more and made some changes to the frame.

The APM got raised up another couple of centimeters on yet more earplugs. It was starting to look a bit silly but I had to get that compassmot result down.

I also changed the landing gear mount to try to make the new gimbal more accessible. I found another old plate and attached this to the bottom of the landing gear mounts. I also mounted rails to the underside of the frame so the landing gear could clip on rather than using hard mounts that were weakening and distorting the lower plate of the main frame. Rather than bolt the gimbal in place I chose instead to mount it using cable ties – this as we shall see later is a good idea!

With these changes the compassmot readings had now come down to just within acceptible limits so it was off to the field once more.

I had also now added a 250mw video transmitter so I could use my new Quanum FPV groundstation to see the view from the GoPro.

The frame now felt a lot better in the air. Altitude and loiter was considerably more locked in and I was finally able to test out the autonomous flight capabilities. There is some flight videos but to be honest they are REALLY boring so I haven’t done anything with them yet – maybe later.

The Quanum gimbal performed well although didn’t feel quite as solid as the Tarot. I liked the setup though and hooking up the pitch control was really easy.

The things I liked about this frame were the automated take-off and landing phases controlled through mission planner. To be honest, the computer was better at landing the thing than I was! The Quanum ground station is excellent and with the Immersion RC Uno reciever I had a nice clear image on the monitor throughout the flight.

I still wasn’t happy with this frame as a serious filming platform though. With the GoPro set to 1440/48 I was getting a lot of landing gear and frame arms in the shot. To top it all off it kept on yawing to one side, which wasn’t ideal for that steady shot.

Enter the HKPilot APM 2.7

HobbyKing came up with the solution in the form of the new HKPilot APM 2.7. Making it easy(ish) to connect an external compass I now had the means to get that problematic compassmot level right down. With one on the way I stripped the frame down again and got going on build three…

Build Three

2014-07-16 21.39.56-960This third and final build was going to be the ultimate solution. With a brand new controller and a custom isolation mount the computer systems were finally coming together. The new Tarot gimbal had arrived and I even splashed out on some carbon props!

Things were looking good. Running the tests showed the effort was worthwhile – compassmot was down to an astonishing 2%. I moved the gimbal forward slightly and trimmed down the landing gear to clear the field of view.

Test flights showed that things were a lot more stable, although I still had some little niggles when flying it manually.

It was a windy day when I finally headed down to the field for some serious filming practice. The first flight went really well. I hopped up to a good altitude and switched to loiter mode. Control was positive and I found I could easily push the frame around the field whilst concentrating on positioning the gimbal through the monitor.

With the first battery spent, I plugged in another and went up again. This time it seemed to be having trouble holding position so with only about 30 meters of air beneath me I hit the RTL switch to get the frame down safely…

Oh dear…

The post-mortem discovered that those carbon props are a problem if you don’t have motors with a T-mount system. I had been forced to use some spacers to fit them on the prop adapters and a couple of the prop nuts had come loose during that first flight – one with fatal consequences.

TOP TIP: Quads just don’t fare too well when you convert them to a tricopter in midair!

10603194_612938768819030_7378516015651413893_nFortunately the damage was minimal. I snapped an arm and the landing gear is toast but that is about it with the exception of a few props. Deciding to cable tie the gimbal in place was a genius solution as the impact simply snapped the ties rather than damaging the gimbal. The flight controller and everything else up top was completely untouched. I’m just lucky I was at 30 meters and not 130.


So that was the sad end to a long and frustrating project. The HobbyKing Q450 Quadcopter is a nice little frame with bags of potential. I got annoyed with how messy the build became and the problems with the undercarriage and gimbal mounting made for a solution that just wouldn’t be repeatable commercially (I had intended to offer this package through my Remote Pilot business).

The external compass is the way to go on this type of frame, espescially if stability and autonomous control are your end goal. The Quanum gimbal is excellent for the money but I’m not sure it quite measures up to the Tarot in terms of performance.

As a side note – the motors, ESCs, Taranis and APM with telemetry never missed a beat throughout.

It’s just a shame it ended the way it did.

I decided after the crash to put this one to bed. I’ve got another HK frame coming that I will play with as a straight X quad for filming but in the meantime I’m working on something even better as a long-term solution to my camera platform needs.

Please be sure to check out www.red20rc.org for more projects, reviews and great content


notsane on September 18, 2014
Next time you might consider an external compass module. It could be located up with the GPS sensor and be further away from the ESCs. I'm using an APM 2.5 with internal compass and HobbyKing 30A ESCs on my tricopter. All 3 ESCs are about 20cm from the APM with no issues. You didn't mention if you reprogrammed the ESCs, but if the deadband timing in the software is mismatched it would cause excessive magnetic noise. You might alternately try replacing the ESCs ... I always buy ESCs that are preflashed with SimonK.

I'd worry about mounting the flight controller on earplugs as this will have some effect on the way the control laws respond. I always balance the props as well as I can and "hard-mount" the flight controller to the frame.

My experience ... for what it's worth ...
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Red20RC on September 18, 2014
Thanks for the comment. Not sure you read the whole article though!

The original had the HKPilot (APM) 2.5.2 with internal compass but was later ugraded to the 2.7 with an external compass. The final compassmot readings with this setup were 2% so I'm pretty happy with that.

The ESCs were flashed with SimonK but I don't think I mentioned that. I always buy or reflash SimonK on all my multirotor ESCs.

The earplugs are actually a suggestion from DIY Drones. They seem to work pretty well but in build three the earplugs were removed and replaced with vibration isolation plate designed for the APM.

There was actually nothing wrong with the flight controller or performance of any of the software. It crashed because I forgot to tighten the prop-nuts and one fell off in mid-air!
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SGRacer on September 18, 2014
Be sure to use locktite on your prop nuts.
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SGRacer on September 18, 2014
Don't get discouraged! I build an SK450 from HobbyKing (basically the same frame but not integrated power) with basic multistar ESCs, APM 2.6 (external compass and gps), sunnysky motors and Gemfan style props. One thing i did do was (as you said) raised the compass/gps to reduce noise and I isolated the APM2.6 on a spare carbon plate (i bought 2 bodies for parts so I used a spare plate) with moongel from amazon. When I look at the vibration logs of the APM i have amazing results.

I would definitely recommend isolating the APM with something better than ear plugs (moongel!) to help make perfect performance and turning your PIDs down. I think i lowered my PIDs about a full point in mission planner.

Is this your first quad your learning on (you mention RTL to land it safely)? Mine was my first, and I tell you, learning to fly on a $300+ custom built quad was fun, but intense and nerve racking. If I were to do it again, I would get a $60 quad with the foam around it from xheli dotcom and learn on that, then move to the big leagues, but that's just me.

Thank you for sharing your story even though it didnt have a happy ending, we all learn from each other.
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Red20RC on September 18, 2014
Hi Nate, thanks for the comment.

This was very much an experiment. I was never a great fan of the frame and it was the layout and mounting options that put me off eventually.

Definitely not my first quad! In fact my second was a SK450 Deadcat (first was a Talon Tri), nice frame but the arms flex way too much. This was my first frame with an APM on it however. In fact I eventually bought a Blade Nano QX to practice round the house with!

I've since replaced the Q450 with a S500 from HobbyKing. That is an exceptional frame - but that's another story (as is what will eventually replace the lot)...
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notsane on September 18, 2014
BTW, I have that Q450 frame and I really like it. Very stiff and hard to break (but not impossible!). I love the power distribution circuit board especially!
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Red20RC on September 18, 2014
I agree. The arms are considerably stiffer than the similar SK450. I might get a replacement and use them in a custom cut frame in the future.
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L_Cooke on September 18, 2014
Shame it didn't have a happy ending...

I recently completed a similar project with similar parts : http://explorer4-quadcopter.atwebpages.com/

Take a look!
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Red20RC on September 18, 2014
Very nice! I'm currently doing something very similar using carbon booms. The TBS Disco layout is really nice and very practical.
Is it a straight X or an offset frame? I only ask because I had trouble with the mixing on the APM with a spider configuration.
I hope they are selling for you!
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apnewton on September 18, 2014
Excellent article, you're good at this.
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Red20RC on September 18, 2014
Why thank you! *blushes*
It keeps me out of trouble!
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butch.bohrer on October 5, 2014
Thanks for the info. I was thinking of getting 1 but now I don't think so. I thought it looked a little weak in designing & seeing what happen to you I was right. Thanks for your video !!!!!!!!!!!!
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Red20RC on October 5, 2014
No worries! It's not a bad frame, I just wasn't didn't like the setup that much.
In am now flying the S500 and can highly recommend it as an alternative.
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HobbyKing Q450 Quadcopter